1. Field of Invention
The present invention relates to instruments used in orthopedic surgery, and, in particular, to a prosthetic inserter, such as an impactor-extractor for use with the impaction and extraction of a femoral provisional component, for example.
2. Description of Related Art
The knee is the joint between the femur and the tibia. The knee joint is formed of a pair of condyles located at a distal portion of the femur, a tibial plateau located at a proximal end of the tibia and shaped to mate with the pair of condyles, and a pair of menisci positioned between the tibial plateau and the condyles. A knee may incur a significant disease or trauma that warrants replacement of the knee with a prosthetic knee implant including prosthetic components such as a femoral component to replace the distal end of the femur, a tibial component to replace the proximal end of the tibia, and a bearing insert to replace articulating tissue between the femur and the tibia.
Orthopedic procedures for the replacement of all, or a portion of, a patient's joint typically require resecting (cutting) and reshaping of the bones of the knee joint to receive such prosthetic components. Procedures for implanting a total knee prosthesis typically involve preparing and reshaping both the distal end of the femur and the proximal end of the tibia prior to implanting the respective prosthetic components. Resection of the femur generally involves making five intersecting generally planar cuts, and resection of the tibial plateau generally involves only a single cut. The amount of bone removed is determined, in part, by the size and type of components being implanted.
During a surgical procedure to implant a prosthetic knee joint, a provisional femoral component and a provisional tibial component can be placed on a distal femur and proximal tibia, respectively, after resecting the distal femur and proximal tibia. The provisional components assist with confirming the proper size and position of the permanent femoral and tibial components. The provisional components typically come in a range of sizes that are identical in size and shape to the permanent components and are typically selected after making a preliminary determination of the proper size of the permanent components. A trial reduction of the knee joint with the provisional components in place may indicate that the preliminary size determination was incorrect, that the gap between the femur and tibia is insufficient, or that some other undesirable characteristic requires the selection of a differently sized tibial or femoral component.
Minimally invasive knee surgeries are becoming increasingly popular and employ, among other things, considerably smaller incisions. Such small incisions lead to tighter working spaces, but promote reduced trauma to nearby tissue and, thereby, accelerate post-operative recovery. Proper insertion and extraction of the provisional components requires reliable grasping and manipulation of the provisional components in a small space.